Subscribers to the data processing services offered by a central computer facility typically rely on the existing telephone system to access the facility. That is, a subscriber will dial the telephone number of the facility, and, when a selected one of plural modems serving the facility answers, the subscriber's computer can then communicate with the central computer. Alternatively, the subscriber's computer may be equipped with an automatic dial-up feature to call the facility and communicate with the central computer. Since there are plural telephone lines into the facility, many subscribers may be served by the central computer simultaneously via parallel telecommunication channels.
For each subscriber call, selection of the particular facility modem to answer is made by a rotary switch based on the order in which the calls are received. Heretofore, a facility modem has been dedicated to each separate communication channel extending from each of the plural rotary outlet ports to the central computer. If the selected modem rings, but for some reason does not answer (ring-no answer-RNA), the subscriber's call is not completed. The subscriber must hang up and then re-dial, hoping this time the rotary-selected facility modem will answer. These ring-no answer conditions not only waste time, but can block rotary selection of other modems capable of answering. The consequent inconvenience os a constant source of subscriber complaint. Another source of subscriber complaint is occasioned when the selected facility modem is found to be busy, i.e., off-hook. Again, the subscriber must hang up and redial.
Modem RNAs and off-hook or busied-out facility modems are conditions typically caused by a malfunction of the facility equipment in the affected communication channels. Since a malfunctioning facility communication channel can not be detected from the telephone utility side of the rotary, it will normally be selected again and again in response to subsequent subscriber calls. Thus, if the communications channels on the facility side of the rotary are not regularly monitored, the existence of facility equipment malfunction does not become known until subscriber camplaints come rolling in. This is particularly so where the facility answering site is unattended.
It is accordingly an object of the present invention to provide improved telecommunications access to a central facility for multiple users of the services afforded by the facility.
An additional object is to provide a call forwarding device for affording ready telecommunications access to a central facility for users thereof.
A further object is to provide a call forwarding device of the above-character for selectively re-routing telephone calls on incoming lines to available outgoing lines pursuant to establishing viable telecommunication channels.
A still further object is to provide a call forwarding device of the above-character for selectively re-routing incoming telephone calls on any rotary lines to other avialable rotary lines as outgoing telephone calls.
Another object is to provide a call forwarding device of the above-character, wherein an incoming call designated for a particular telecommunication channel is automatically re-routed to an alternative telecommunication channel when the designated channel is found to be incapable of handling the call.
An additional object is to provide a call forwarding device of the above-character which is selectively capable of operating in several different call forwarding or re-routing modes.
Yet another object is to provide a call forwarding device of the above-character, which is capable of accumulating a record of each re-routed call, such that defective telecommunications channels can be readily identified and expeditiously remedied.
A still further object is to provide a call forwarding device of the above character, which is efficient in construction, convenient to implement and control, and reliable in operation.
Other objects of the invention will in part be obvious and in part appear hereinafter.